Submersible motor-pump assembly



June 7, 1960 J. T. MAYNARD SUBMERSIBLE MOTOR-PUMP ASSEMBLY \i'iiinml NENTOR,

H'Orneqs BYWMQLM I n l w 4 I n Mm rllllllllr m United States PatentSUBMERSIBLE MOTOR-PUMP ASSEMBLY John T. Maynard, West Allis, Wis.,assignor to 0. Smith Corporation, Milwaukee, Wis, acorporatlon of NewYork Filed May'7, 1956, Ser. No. 583,046

1 Claim. (Cl.'103-87) This invention relates to a submersible motor-pumpassembly and in particular. to.amotor-pump assembly havinga-rnulti-stage pump.

The general construction of a submersible' motorpump assembly comprisesa separatemotorand. pump unit having the respective shafts coupledtogether and adapted to be lowered into a well with the motor and thepump' submersed into the well liquid. A spacer structure secures thepump and the motor in spaced relation toallow the water to enter thelower end.of the pump which forces the water upwardly through a stringerpipe leading to the top of the well. vided with a thrust hearing at itslower end to take up the thrust forces during operation. The motor andpump ice which is shown in thedrawing. At its upper end-the rotor issupported by-a radial bearingltl, more. fully) described hereinafter.The power lines 11 which are connected to a field winding 12 within thestator extend from the stator assembly 1 through an opening in the,

upper stator end member 13. The opening is sealed by potting with anysuitable resin 14 to prevent fluid leakage;

into the stator assembly. The shaft 9 of motor, 1 extendsupwardlythrough a portion of the spacing: member 3, and is splinedon itsexterior periphery as at 15 to mate with an internally splined recess inan enlarged end por.-;

tion 16 .of the pump shaft 17.'

The splined coupling rotatably. binds and axially alignsv the motorshaft 9 andthepump shaft 17:. As the upper motor radialbearing is toradially supportthe lower end of the pump shaft, a coupling or. otherrelatively rigid,-

' through adischarge nozzle 21 which is connected to a are each-providedwith their own upper and lower radial bearing to radially support and 1align'lthe respective shafts. a

In accordance with the present invention; the spacer member ispreferably integrally cast [with the upper motor bearing housing and thebase for thepump as sembly. Whenintegrally cast, the'conventionalpumpsuction castingis eliminated with the up'per motor housing serving thedual purpose of a bearing support and .alsosupporting the pump. Theconstruction of the present invention eliminates the'lower pump hearing.The cast spacer is smaller than the conventionalspacer structure and theupper radial bearing of the motor also radially supports the lower endof the'pump shaft and consequently serves'as the lower pump hearing.

The present invention providesasimplified, compact motor-pump assemblywith reduced. cost of material and assembly.

The drawing furnished herewith illustrates..-the-. best mode presentlycontemplated forcarrying out. thelinvem tion. I V

In the drawing:

Figure 1 is an elevational view of a submersible motorpump-unitembodying the invention with parts broken away and sectioned; 1

Fig. 2 is a view taken on the line 22 of Figure 1;

Figure 3 is a fragmentary elevational view with a portion broken awayand sectioned of a spacer member shown in Figure l; and

Figure 4 is a perspective view of an integrally formed bearinghousing-spacer-pump base member.

Referring to the drawing and particularly Figure 1, a submersible motor1 is coupled in driving relation to the lower end of a multi-stage pump2 and is connected in spaced relation thereto by a spacing member 3. Theunit is lowered into a well 4 from which water 5 is to be pumped withthe motor 1 and at least the lower endiof' stringer tube .22.Aconventional coupling 23 threads.

- onto the outer. end. of the discharge nozzle 21 and the The motorispro stringer. .tubea22 .toconnect them together. A floatvalve 24 inthe coupling 23 prevents the Water once pumped into the tube 22.fromreturningrto the well.

' Each. stage of the pump 2 comprises a housing. 25 within; which. animpeller. 26 rotates .and centrifugally forces .thewater to thesucceeding. stage. Eachimpeller 26isalockedto..the,,pump shaft 17 by akey 27. The

ing an annular stator assembly 7 with a rotor 8 rotatably mounted withinthe bore of the stator. The rotor is secured to a motor shaft 9 and issupported at the lower end by a thrust bearing and a radial bearing,neither of housings 25 are stacked one upon' another with theafirststage resting on theisbase 19. The lower periphery of each housing 25:is recessed-to accommodateanupstande ing flange portion "28 oftheimmediately lower housing except for the first stage;which..receives. an upstanding flangeaportion 29 of the base19. The pluralityof .pump stages are secured in..stacked"relation by a sleeve casing 30.whichis crimped at each end upon projections 31and32rformed-respectively on the lower surface of the base portion 19 andthe discharge nozzle 21 of the .pump' 2. Thespacing member 3,aperspective view being shown in Fig. 4, comprises an upper motorbearing housing 33 and theg pump base 19 .which .ar'etconnected by aplurality of spacer struts 34 formedintegrally at their ends with thehousing and base. The spacing member 3is preferably made as ,.a. singlecasting to obtain maximum economy in. construction and-assembly.

The upper bearing housing 33 is a generally thick,

circular member with a downwardly depending hub 35 having a central borethrough which the motor shaft 9 extends. The radial bearing 10,previously described, is secured within the hub 35.

The spacing member 3 is secured to the stator end plate 13, with the hub35 extending into the rotor cham- 'ber 36, by a plurality of bolts 37which pass through suitable openings in the housing 33 and thread intosuitably tapped openings in the end plate. A lead-in plug 38 extendsthrough the circular member of housing 33 for passage of the power lines11.

The radial bearing 10 secured within the bore of the hub 35 maintainsthe radial alignment of motor shaft 9 and pump shaft 17. A shaft seal 39is disposed within a recess in the housing through which shaft 9 passesto restrict entry of water and foreign matter into the rotor chamber 36and a seal cover 40 overlies seal 39 to frictionally hold it in place. Asand slinger '41 is secured.

tothe shaft immediately adjacent the shaft seal 39 to centrifugallythrow larger foreign particles from about the seal.

A radial bearing 42 is provided at the upper end of the pump shaft 17and a radial bearing, not shown, is provided at the lower end of themotor shaft 9 to complete the radial support for the shafts 17 and 9.

The motor 1 is adapted to. run with the rotor chamber 36 filled withwater. As more clearly illusrtated in Figs. 2 and 3, to initially fillthe rotor chamber with Water, a water inlet is formedby a tapped opening43 extending laterally inwardly'within an enlarged portion 44 on the topof the circular member of housing 33 and into communication with alongitudinal opening 45 in the housing adjacent the hub 35. The opening45 is in communication with the rotor chamber 36 which may be filledwith water and a plug 46 then threaded into the lateral opening 43 toseal the passage.

A similar passage is also formed in circumferential spaced relation tothe first passage by a lateral opening 47 formed in an enlargedportion48 and longitudinal opening 49 in the housing .33. The latter passageallows the air in the rotor chamber 36 to escape while filling withwater. The lateral opening 47 is also tapped to receive acorrespondingly threaded plug 50 which seals the passage after the rotorchamber 36 is filled. This prevents formation of air pockets and allowsrapid filling of the rotor chamber.

The four circumferentially spaced struts 34 are integrally formed withthe housing. portion of the spacing member 3 and hold the integrallyformed pump base 19 in vertically spaced relation to the motor 1 tothereby allow entry of water to the inlet 18 of the pump 2. Each strut34 extends radially from the structure of seal 40 to 18 disposed belowthe upper level of the water; The unit is started and stopped byremotely controlling the energization of the stator winding 12 via thepower lines 11.

When energized, the motor 1 drives the pump 2 which draws water inthrough the lower end of the pump and raises it through the various pumpstages, discharging it through the discharge nozzle into the stringertubing which carries the water from the well.

The combined bearing-spacer 3 permits the entryof water into the lowerend of the pump assembly. .As previously noted, the spacing struts areshortened to a minimum consistent with a satisfactory water flow.

the outer edge of the housing. The inner vertical surface751 of eachstrut 34 is generally vertical .with the outer vertical surface 52tapering inwardly and upwardly to the base portion 19 with thecircumferential lip 31,

about which the pump casing 30 is crimped, encircling the upper ends ofthe struts.

-.The length of the struts 34 is maintained at a minimum consistent withallowance for suitable flow to the pump opening 18 and coupling of themotor shaft, 9 and the pump shaft 17. In this manner, the pump shaft 17is maintained and radially supported in alignment without the necessityof a lower radial bearing for the pump.

j; The base portion 19 is generally ring-shaped and has the lip 31 andflange 29 integrally formed with the struts 34. i T I i A screen 53encircles the struts 34'and the'circular portion of housing 33 andtapers inwardly as at 54 to dispose the top edge within the dependingbase lip 31. Set screws 55 thread into housing 33 and secure the screenin position. I I p In operation, the submersible motor-pump unit islowered into the well 4 with the motor 1 and water inlet The presentinvention eliminates the radial bearing for the lower end of the pump.and permits a substantial reduction in the size ofthe spacing structure.By forming the bearing housing, strut spacers and pump base as anintgeral cast unit substantial economy of materials and assembly isobtained.

Various modes of carrying out the invention are contemplated as beingwithin the scope of the following claim particularly pointing out anddistinctly claiming the subject matter which is regarded as theinvention.

I claim: 1 r

A submersible motor pump assembly comprising an electric motor, aspacing member mounted on said motor and having a plurality of openingstherein for passage of fluid to be pumped and a hub integral therewithand extending within said motor, a shaft disposed Within the motor anddriven thereby and extending within said hub, a pump unit mounted on thespacer member and having a plurality of vertically stacked impellerslocated-therein and a shaft extending through the impellers to which theimpellers are secured and depending into said spacer member intoengagement with the motor shaft to be driven by said motor shaft, abearing confined within said hub in engagement with the motor shaft tosupport the motor shaft and pump shaft against radial thrust and therebyeliminate a separate bearing support for the lower end of the pumpshaft, and a shaft sealing means disposed around the motor shaft withinthe spacing member and at the end of the bearing exposed to the fluidbeing pumped to restrict entry of fluid and foreign matter to thebearing and motor.

References Cited in the file of this patent, UNITED STATES PATENTS2,043,236 Conant June 9, 1936 2,366,964 Howard Jan. 9, 1945 2,648,286Bergh Aug. 11, 19.53 2,667,128 Bergh Jan. 26, 1954 2,787,960 Wightma'n'Apr. 9, 1957 Rice .Dec. 17, 1957

